Respuesta :

Answer:

[tex]f(3)=-f(9)[/tex]

Step-by-step explanation:

We know that f(6) = 0 from (i), so let's do x = 3.

[tex]f(3+3)=f(3)+f(9)[/tex]

[tex]0=f(3)+f(9)[/tex]

Therefore,

[tex]f(3)=-f(9)[/tex]

I hope it helps you!